Dishwashing machine



April 26, 1932-. I E; D WATT ETAL I 1,855,848

' DISHWASHING MACHINE Filed July s,- 1928 s Sheets-Sheet 1 April 26,1932- E. D. WATT ET AL DISHWASHING MACHINE Filed July 5, 1928 3Sheets-Sheet Ira/1n.

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desirable to utilize a small amount of a Patented Apr. 26,

UNITED srArEs PATENT OFFICE ELIHU I). WATT, OF LA' GRANGE, WILLIAM J.IRWIN, OF CHICAGO, AND GEORGE VIRKUS, OF LA GRANGE, ILLINOIS, ASSIGNOBSTO THE GONOVEE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOISDISHWASHING MACHINE .A piication filed July 5, 1928. Serial No. 290,344.

The present invention relates to impellers for'spraying liquids andparticularly relates to impellers for use in the spray-projection typeof-dishwashing machines.

In these spray-projection machines it is cleansing liquid and to throwthe cleansing liquid radially upwardly and outwardly from a low leveltoward, and upon, dishes and similar objects at a high velocity. Thedishes at all times are supported above the level of the pool ofcleansing liquid in the bottom of the machine and the cleansing actionis effected by the projected or reflected spray. It is desirable toproject the liquid spray at such a velocity that it will have a forcesufiicient to dislodge the adherent dirt from the surfaces of the dishesand other objects.

The object of the present invention is to provide an improvedliquid-projecting impeller which is particularly adapted for use in thistype of washing machines.

Another object of this invention is to pro vide an impeller which isadapted to elevate and project effective quantities of cleansing liquidupwardly and outwardly at a sufficient velocity to cleanse the dishesand similar articles arranged within a considerable area thereabout.

I A further object of this invention is to provide an impeller forspray-projection type dishwashing machines which will uniformlydistribute a small volume of cleansing liquid throughout the desiredareas of the washing I chamber of the machine.

The following drawings represent several embodiments of the invention towhich the invention, however, is by no means restricted Figure 1represents a vertical sectional view of a dishwashing machine with theimpeller in position;

Figures 2, 3 and 4 represent enlarged side,

top and sectional views of the embodiment of the impeller shown inFigure 1; and

Figures 5, 6 and 7 represent side, top and sectional views of a modifiedimpeller.

In Figure 1 the tank of the dishwashing machine 11 is provided with aremovable cover 12 and supported upon legs 13. The impeller is disposedcentrally in the lower portion of the tank 11 and is actuated b means ofa vertical shaft 14 which exten s through the bottom of the tank. Thelower portion of the shaft 14 is connected by means of the insulatingcoupling 15 to the upwardly projecting shaft 16 of the motor 17 The'motor 17 is suspended from the tank 11 by the bearing member 18 and issupported and centered by the spider 19 which is attached to the legs13.

The bearing member 18 is provided with a central tubular bearing 20which is adapted to extend upwardly into the tank to a position abovethe normal water level. A downwardly facing cup-shaped portion 21isattached to the lower portion of the central tubular portion 20. Atthe lower side of the cup 21 is a circular flange 22 which is providedwith a circular shoulder 23. The shoulder 23 is adapted to cooperatewith the recess 24; in the end bell of the motor 17 to center the motorand its shaft. The bolts 25 are adapted to bind together the flange 22,

the central portion of the spider 19 and the frame of the motor 17 andmaintain the cooperating shoulder 23 and recess 24 in osition; The endbell of the motor an the coupling 15 which turns with the shafts 14 and16 forms alower guide. The coupling 15 preferably consists of a moldedpiece of bakelite or other insulating material feathered to the shafts14 and 16 and surrounded by a steel shell. The shaft- 16 is additionallyinsulated from the shaft 14 by a piece of insulating material 27 whichis placed watertight in the gap between ends "of the shafts. Thematerial 27 may be rubber. The bearing member 18 is held in position bymeans of a nut- 28 which is adapted to coact with the flange 29 of thebearing member 18 to clamp the bottom of the tank 11 between the washers30.

In the tank 11 is positioned. a dish rack 31 composed of wires which maybe of any suit:

able construction and is intended to support dishes or similar objectsin the space above the impeller and above the pool level. The dishes orother similar objects are so supported by means of the rack 31 that thespray projected by the impeller will contact with them at such an angleas to cleanse them most effectually. Normal water level when theimpeller is at rest is indicated at 32. It will be noted that the normalwater level is so established that the impeller is only partiallyimmersed.

The impeller, which constitutes a liquidpropelling or circulatingdevice, is positioned in the lower central part of the tank and sodesigned as to elevate liquid from a small area of the pool at about thecentral axis of the machine, and then project the elevated liquidupwardly and outwardly at a high velocity in the form of sheets orcoarse spray.

The impeller, shown in Figure 1 and more fully in Figures 2, 3 and 4comprises a cylindrical hub or axial portion 35 and two upwardl-yconcave spoon-shaped or concaveshaped projectors 36 and 37. Continuouswith the lower inclined part of the spoonshaped or concave-shapedprojectors are the helical portions or elevators 38 and 39 which extenddown to a point below the contemplated surface level of the liquid pool.The spoon shaped projectors and the downwardly extending helicalelevators continuous therewith are attached to the outside of thecylinder 35. In the examples illustrated, the elevator 38 is showncontinued downward considerably farther than the elevator 39, but it isobvious that the elevators may be made of equal length. As shown, thelower terminus of the elevator 39 is about 180 from the radial edge 40of the conjoined projector 37, while the elevator 38 continues throughabout 540 from the radial edge 40 of the concave projector 36. The pitchof the upper inclined surfaces of the elevators 38 and 39 is such thatthe water will be elevated onto the upper portion of the concaveprojectors as the device is rapidly rotated. The upper terminal portionof the spoon-shaped projector, which is attached to the cylinder 35,extends approximately vertically for a short distance radially from thecylinder, and as it progresses farther from the cylinder, turnsgradually from the vertical and assumes an in wardly inclined form, asindicated at 41 in Fig. 3. The height of the upper edge of the projectorincreases as it progresses away from the cylinder 35 until at 42 itreaches its maximum height. which is at a substantial elevation abovethe top of said cylinder.

. In the embodiment illustrated, this high point 42 is on approximatelythe median line of the projector blade, but its location will begoverned to some extent with reference to the relative diameter anddepth of the tank in which it is to operate. The height of the outeredge of theprojector decreases rather rapidly from the high point 42, soas to form a rather sharply inclined margin 43. As the terminating upperedge .of the inclined surface is approached. the horizontal width of theinclined surface increases so that at the point of about 45 horizontallyin advance of the vertical termination 40 in the embodiment of theinvention shown the. impeller will achieve its maximum width asindicated at 44 see Figure 3). From the place of maximum width 44. thehorizontal width of the inclined surface very rapidly decreases until itcoalesces with the vertical terminal part 40 and lower inclined parts 38and 39. The vertical surface 40 projects radially from the cylinder 35.If desired, however, this vertical surface may be attached to thecylinder 35 at some other angle approaching a tangent. The inclinedsurface is so widened and provided with an upturned lip or edge 45 as togive the desired direction to projection of the spray under thecentrifugal force tending to throw the water outwardly off the blade.

Both the concavity and the pitch of the elevating and deflectingsurfaces increase as the top of the impeller is approached in theembodiment shown. If desired both the elevating surfaces and the spoonshaped deflectors maybe made of approximately the same concavity and ofapproximately the same pitch or inclination. If the pitch is increasedit is preferable to decrease the angle of turn around the cylinder 35 soas not to unduly increase the height of the impeller 34. The presentpitch varies from about 10 to the horizontal at the bottom to 80 to thehorizontal at the top. If desired the pitch of the entire elevating anddeflecting surface may be caused to range from 45 to to the horizontal.When the pitch is so increased, it is desirable to decrease the angle ofturn from a range of 180 to 720 toarange offrom 45 to 180. To increasethe concavity of the lower elevating and deflecting surfaces the outerterminating edge may be farther elevated and the center of the-surfacesmay be caused to be materially depressed below the outer terminatingedges.

The position and shape of the deflecting portion may be considered to bedetermined by three helices or portions of helices. The

inner helix will be the line of attachment line or helix at the upperpoint of attachment to the axial portion. The central helix or medianline will be formed by the center line between the inner and outerlines. When the outer helix is a continuous curve the inner median andouter lines will meet at the highest point of attachment of thedeflecting portion to the cylinder 35. As will be seen from thedrawings,v the inner median and outer lines diverge from their point ofintersection to a maximum'distance apart. and then converge toward thelower part of the deflecting portion". Cpnsidered conversely, thedistance between the lines increases from the lower part of thedeflecting portion until a maximum distance apart is reached, from whichthe lines converge. The concavity of the defleeting portion causes theouter line to be above the inner and median lines below the point ofmaximum distance apart In the modification shown, this relationcontinues to the point of intersection.

- The impeller 34 is so positioned in the pool that the lower portionsof the spoon-shaped deflector will be immersed in the liquid poolwhereas the upper portions will be' unimmersed. The upper part of thecylindrical shell is closed and is welded to a nut 46 into which theupper part of theshaft 14 is adapted to screw by means of a threadedportion of decreased diameter, the threads Y so erably its largestdiameteris less than one-' being arranged to set up in the direction ofoperating rotation of the im eller so that it will not tend to unscrewduring bperation.

' The cylinder shell 35 encloses and surrounds the upwardly projectingtubular bearing 20 (see Figure l) and will maintain an air pocket aboutthe place of entrance of the shaft 1-1 and into the tank 11 materiallydecreasing possibility of leakage. 1

Figures 5, 6 and 7 show asli htly modified embodiment of the impellershown in Figures 1 to 4. In Figures 5 to 7 the down- -wardly-extendinginclined surfaces constitute continuations of the concave projectors 36and 37 and terminate about 180 from the point ofnttachment of theconcave projectors 36 and 37 to the cylinder 35, the elevating surfacethus being considerably shorter than in the other form. It may bedesirable in certain instances to increase the pitch of such elevatingsurface. As shown in Figures 5 to 7 the elevating surface has the samepitch as the impeller shown on Figures l'to 4, but

if desired, the lower edges 50 and 51 may be caused to be in a positionmuch farther down the shaft and they may extend from the upper terminusless than 180.

The impeller device 34 preferably occupies 1 but a minor portion of thehorizontal internal area of the washing machine and pref third of theinterior diameter of the tank. The impeller may be so positioned thatabout 50% of its height is immersed in the liquid per minute, preferablyabout 1,750 'tions per minute.

21", diameter the impeller may pool, but this may vary between 25 andThe impeller is preferably rotated by a motor disposed below the tankand directly driven thereby at a rate of 1,0002,000 revolutions revolu-For a tank have a dlameter of 5 to 6 inches outslde diameter and theblade or inclined elevating and deflecting surface may have a maximumwidth of 2 to 2 ,4 inches. If it is assumed that this impeller isrotated at a speed of 1,750 B. P. M. the water projected from its 7maximum will have a speed of about 2,500 to 2,600 feet permlnute. For atank of 26 diameter-,theimpeller may have an outside diameter of 6 to 7in'cheswith a maximum width of defiecting surface of about 2 to 2%inches. If it is assumed that it rotates at 1.750 R. P. M. theperipheral speed of the projected water will be about 2,900 to 3.000feet per minute. In general the diameter ot' the impeller will vary withthe diameter of the tank. The impeller when in 1110- tion, traveling asit does faster than the water, increases the volume of water on thevaries. It will elevate the required amount of water without thenecessity of walls or a casing to hold the water on thevanes. At thepoint where the water leaves "the. concave projector it will be radiatedin fan" shape along tangents to the circular path of elevation, thegreatest volume being delivered at an approximate angle of 45. tothehorizontal and to the axis of the machine. 1

The construction of the impeller 34 [may be modified by eliminating theapron shell 35 and by attaching the elevating and 'defleeting surfacesdirectly to the central shaft 14. In this case itwould-be necessary toprovide a bearing in the bottom of the tank and suitable stufiing boxarrangementslto prevent leakage. The impeller as shown is preferablyconstructed by first forming the inclined va nestinto the desired shapeand I then attaching theseiuclined vanes to the cylindricalshell 35. Theimpeller or the vanes mayalso be made by casting or mold ing'. vThepreferred embodiment of theinvention utilizes two vanes. The number maybe increased to more than two or only one vane may be utilized. Theimpeller should not extend above the normal static water level more,than its maximum diameter and it preferably should notextend much morethan one-half of i s diameter. The top of the impeller shouldalso besubstantially below the dishes. g I. ;{-i y y By theexpression;spdon-shaped as used herein in describingthdiurface contourof the impeller blade "portions, is meantthat' they are ofconcavecontour transversely with up ardly directedlouter edges. byvirtue of which the centrifugally propelled liquid is given an upwarddirection.

lVhat is claimed is:

1. An impeller tor dishwashing machines, comprising an axial portion andan upwardly progressing helicoidal vane extending out wardly therefromand presenting a transversely concave upper surface. the Width of saidsurface and the concavity thereof gradually increasing toward the top ofthe impeller.

2. -'.n impeller for dishwashing machines adapted to elevate and projectliquid from a pool, comprising an axial portion and an upwardlyprogressing helicoidal vane extending outwardly therefrom, the medianline of the upper surface of said vane and the lines of its inner andouter edges being so related that the distance therebetween increases toa maximum distance apart as they ascend and then decreases to the upperextremity of the inner'line, the median and inner lines being below theouter line.

3. An impeller for dishwashing machines adapted to elevate and projectliquid from a pool. comprising a hub portion and helicoidal vanesprojecting outwardly therefrom and extending part way around the hubportion, said vanes increasing in width and assuming a transverselyconcave contour as the top of the impeller is approached, the lines ofattachment of'said vanes to the hub portion forming helices, the uppercontinuations of which are approximately vertical, and the outer edgesof said vanes being turned upwardly above said line of attachment ofsaid vanes.

4. An impeller for dishwashing machines comprising a hub portion and ahelicoidal vane extending outwardly therefrom, said vane having acontinuously curved outer edge throughout its length and being ofgradually increased width toward its upper end and having its uppersurface transversely concave as it approaches its upper terminus.

5. A spray-projecting impeller of the upright type, comprising an axialportion. and a concave helicoidal, deflecting portion mountedtherearound, the traces of progressive vertical radial planes throughsaid defleeting portion for an angle of at least substantially 90 fromthe upper terminus of said deflecting portion being curved upwardly attheir outer ends.

6. A spray-projecting impeller of the upright type, comprising avertical axial portion, a concave helicoidal deflecting portion ofgradually increasing upward inclination I mounted around said axialportion, said concave deflecting portion having an upturned outer edgeforming a continuous curve which gradually increases in distance fromsaid axial portion to a maximum, and then gradually decreases indistance to meet said axial portion at its upper end.

7. A spray-projecting impeller of the uprighttype, comprising averticalaxial portion, and a concave helicoidal deflecting portion of increasingupward inclination mounted therearound, the inner, median, and outerlines of said portion meeting adjacent the upper end of said axialportion and then declining therearound in continuous curves atincreasing distances apart, to a maximum and then gradually approachingeach other toward the lower part of said deflecting portion, the outerof said lines being above said inner and median lines below said pointof maximum distance.

8. A spray-projecting impeller of the upright type, comprising an axialportion, and an inclined concave helicoidal deflecting portion having anouter edge which recedes from the upper part of said axial portionaround said axial portion in a gradual and continuous curve reaching amaximum distance from the axial portion and then gradually approachingsaid axial portion, said outer edge being above the inner and medianportions of said deflecting portion below the point of maximum distancefrom said axial portion.

9. A spray-projecting impeller of the upright type comprising a verticalaxial portion, and a concave helicoidal deflecting portion mountedtherearound, said concave defleeting portion having an upturned outeredge which increases in distance from the axial portion to a maximum,and then de,

creases in distance from said axial portion toward the top of saidconcave deflecting portion.

10. A spray-projecting impeller of the upright type, comprising avertical axial portion, and a helicoidal concave deflecting portionmounted therearonnd, the inner, median, and outer lines of said concavedeflecting portion diverging to a maximum distance apart, and thenconverging toward the top of said concave deflecting portion, said outerline being above the median and inner lines below the point of maximumdistance apart.

In twtimony whereof we have hereunto subscribed our names.

ELIHU D. WATT. XVILLIAM J. IRWIN. GEORGE VIRKUS.

